Conventionally, there has been known a luminaire including an active sensor for detecting a moving object such as a human body by use of transmitting and receiving radio waves, which is disclosed e.g., in Document 1 (JP 2009-168778A). In the luminaire disclosed in Document 1, the active sensor is installed to a ceiling to send radio waves toward a floor surface. In this luminaire, a cover member is provided near an antenna of the active sensor so that a transmission area of the active sensor is not covered by the cover member. The cover member is made of material having a radio wave blocking property.
In the luminaire disclosed in Document 1, the cover member is provided in order to reduce an influence of reflected waves coming from another direction, and is located apart from the active sensor so as not to affect a detection area of the active sensor. Accordingly, unnecessary external radio waves and reflected waves are less likely to reach the antenna.
In luminaires such as the above conventional example, desired detection area of an active sensor (radio wave sensor) would vary depending on an installation location of the luminaire. However, in order to obtain a desired detection area of the radio wave sensor in the luminaire of the above conventional example, arrangement of the radio wave sensor needs to be changed by, for example, adjusting a tilting angle of the radio wave sensor. Therefore, a setting work of the detection area of the radio wave sensor may be difficult.